Door operator control

ABSTRACT

A door operator control is disclosed in which a limit switch controls the output of a motor which is connected to move the door. This may be a down limit switch for a garage door, and the down limit switch is actuated as the door reaches the down limit position. Cycling means which includes a reference dimension and differential measuring means is connected to move the limit switch back and forth in accordance with the door opening and closing movements. Thus, as the door sill gradually moves up and down due to changes of ambient conditions, e.g., freezing of the ground under the sill, the limit switch is moved back and forth to be actuated at different positions in accordance with the changing ambient conditions. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.

United States Patent 191 Deming et al.

[451 Nov. 26, 19 74 DOOR OPERATOR CONTROL Inventors: Andrew F. Deming, Alliance; Alvin J. Carli, Sebring, both of Ohio Assignee: The Alliance Manufacturing Company, Inc., Alliance, Ohio Filed: Nov. 23, 1973 Appl. No.: 418,545

References Cited UNITED STATES PATENTS 4/1969 Carli 200/47 9/1973 Tenniswood et al 200/47 Primary ExaminerHerman l-lohauser Attorney, Agent, or FirmWoodling, Krost, Granger [57] ABSTRACT A door operator control is disclosed in which a limit switch controls the output of a motor which is connected to move the door. This may be a down limit switch for a garage'door, and the down limit switch is actuated as the door reaches the down limit position. Cycling means which includes a reference dimension and differential measuring means is connected to move the limit switch back and forth in accordance with the door opening and closing movements. Thus, as the door sill gradually moves up and down due to changes of ambient conditions, e.g., freezing of the ground under the sill, the limit switch is moved back and forth to be actuated at different positions in accordance with the changing ambient conditions. The foregoing abstract is merely a resume of one general application, is not a complete discussionof all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.

24 Claims, 10 Drawing Figures PATENTEL WV 2 6 I974 3351.125 SHEEIE'UF 3 1 Fig. 5

PATENTEL HUVZSISH SHEET 3 OF 3 IIHIIHn irlis llllHlllu I III, 1:

. I 1 DOOR OPERATOR CONTROL BACKGROUNDOF THE INVENTION Governmental regulations are becoming more strict on many mechanisms including garage door operators.

.A safety requirement recently imposed is that if a 'ga- .rage door meets an obstruction during the closing direction of movement, then the door should not only stop but should also reverse direction. This is the case if the obstruction is above the floor more than a 2 inch thick lumber block, about 1 9/ 16 inches. This is to prevent the suffocating deaths of small children and pets which might be trapped under a closing garage door. Numerous circuits have been proposed to accomplish this stopping and reversing for upward movement of the garage door. However, in many parts of the country especially in the northern parts, the freezing and thawing conditions of a garage floor or sill underneath the door may change the down limit position of the door by as much as an inch or more. Various types of garage doors are in use in the United States including sectional doors running on a curved track, one-piece.

doors moving on a combined horizontal and vertical track, one-piece doors moving on linkage between vertical and horizontal positions, and one-piece doors pivoted at an elevation approximately at the midpoint of the door. These various types of structures and others have different movements of the door operator carriage relative to the actual door movement near the down limit position.

The sectional door running on a curved track has a typical door operator which acts through a toggle mechanism to effectively lock the door closed so that it cannot be forced open from outside. This toggle mechanism means that, just prior to the down limit position, the door carriage has considerable movement relative to a small movement of the door. Accordingly with a door sill whchmight move up and down by one inch due to freezing and thawing, the door operator carriage running on a guide rail might have a changing position of as much as three or four inches as its closed limit position. This changing limit position by as much as three or four inches of the door carriage greatly complicates the problem of complying with the aforementioned safety regulations of reversal of the door as the door meets an obstruction more than 1 9/16 inches from its down limit.

Accordingly, an object of the invention is to provide a door operation control which obviates the abovementioned disadvantages.

Another object of the invention is to provide a door operator control with a gradually changing position at which there is an actuation of a sown limit switch.

Another object of the invention is to provide a door operator control with. a traveling limit switch which moves along the guide rail for the door operator carriage and gradually changes positions therealong in accordance with'the changing ambient conditions.

Another object of the invention is to provide a door operator control wherein cycling means is provided to relatively move the point of switch actuation by actuator means in accordance with gradual changes in a limit position of the door.

' Other objects and a fuller understanding of the invention and claims, taken in conjunction with the accompanying drawing.

tion. may be had by referring to the following descrip- 2 BRIEF DESCRIPTION OF THE DRAWINGS. FIG. 1 isa sideelevational view of a door operator control embodying the invention;

FIG. 2 is a bottom view of FIG. 1;

FIG. 3 is a left end view of the control of FIG. 1; FIG. 4 is an elevational view of a'garage door on .which the door operator control may be utilized;

FIGS. 5 and 6 are alternative types of garage doors on which the door operator control may be used;

FIG. 7 is, a schematic wiring diagram of the electrical portion of the garage door operator;

FIG. 8 is a side elevational view of a modified form of door operator control;

FIG. 9 is a bottom view of the door operator of FIG. 8; and,

FIG. 10 is a sectional view on line l0-l0 of FIG. 8.

2 DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1, 2, and 3 show a door operator control 11 which may be used with a motor 12 having an output 13 connected to move a door 14 between open and closed limit positions. The door 14 may be any one of several types, for example those shown in FIGS. 4, 5, and 6, and the door may be adapted to have a gradually changing limit position due to gradually changing ambient conditions. The motor output 13 is connected to move a door carriage 16 along a guide rail 17. The carriage 16 is connected by an arm such as an L-shaped arm 18 tomove the door 14 between open and closed positions. The motor operated door operator may be such as that shown in US. Pat. No. 3,694,664 or may be of the worm drive type such as shown in US. Pat. No. 3,719,005. In such case the motor 12 rotates a worm 19 which drivesa half nut 20 within the door carriage 16 to traverse such carriage back and forth along the guide rail 17, and hence open or close the door.

The control 11 includes limit switch means which includes a down limit switch 21 and an up limit switch 22. Actuator means 23 is provided for this limit switch means. The limit switch 21 is mounted on a frame 25, and the actuator means 23 is mounted on a frame 26. The limit switch means in connected in an electrical control circuit 27, shown in FIG. 7, to control the motor output 13. In this preferred embodiment, it controls the de-energization of the motor 12. In so doing it controlsthe motor output in at least one of opening and closing movements. Cycling means 29 is provided to relatively move the point of switch actuation by the actuator means in accordance with changes in a limit position of the door 14. This cycling means 29 is responsive to a cycle of an opening and a closing movement of the motor Output 13. In this preferred embodiment the cycling means'29 is connected to move the limit switch 21 back and forth along the guide rail 17.

The carriage 16 slides inside a channel in the guide rail 17 and as shown in FIG. 3, the switch frame 25 also slides in the same channel. The limit switch 21 is Of the type having first and second contacts 31 and 32 with the first contact 31 being grounded. Accordingly, when the two switch contacts are engaged, this grounds the second contact 32 to de-energize the motor 12 as explainedbelow in connection with FIG. 7.

The switch frame carries a rotatable axle 33 on which is fixed a one-way ratchet wheel 34 and two friction tired wheels 35 which roll on the under surface of cooperate with the ratchet wheel 34. The actuator pawl 39 is fastened to the actuatormeans frame 26 in an adjustable length manner by the screw 41. FIG. 2 shows a bottom view of the door operator control 1 1 with the L-shaped arm 18 removed in order to show the adjusting screw 41.

The electrical control circuit shown in FIG. 7 may be that as used with many different forms of garage door operators, for example US. Pat. No. 3,694,664 or US. Pat. No. 3,719,005. FIG. 7 is a combined schematic di agram of the electrical circuit and a pictorial representation of a torque switch 44. The control circuit 27 is adapted to be energized by an Ac source 45, for example a -l 15 Volt Ac source, which energizes a transformer 46 having a low voltage secondary 47 with one end connected to ground 48. The voltage source is also connected by means conductors 49, 50 to energize the motor 12. This motor 12 has first and second motor windings 51 and 52 and a capacitor 53 connected thereacross to establish reversible rotation of the motor rotor 54. The rotor 54 drives through a friction clutch 55 to the motor output 13 which may be considered the door carriage 16. The motor output also goes through a one-way clutch 56 to drive the torque switch 44. The torque switch 44 includes a metal plate 59 journalled for rotation and has a'hub 60 engag'eable by a grounded plunger 61, which is thrown outwardly by centrifugal force to open the switch, and when the speed of the hub 60 and plate 59 slows down as when the door meets an obstruction, then this grounded plunger contacts the hub 60 to also ground such hub and plate. The metal plate 59 carries first, second, and third contacts 62, 63, and 64. The first contact 62 is designed to have a momentary contact with a contact blade 65 as a plate 59 swings clockwise from the solid line position shown to the dotted line phantom position shown. The second contact 63 is designed to be in engagement with a second contact blade 66 in the position shown in FIG. 7 and when a weight 68 on the metal plate 59 causes this plate to move clockwise to the phantom position, then the third contact 64 willbe in engagement with the second contact blade 66. The one-way clutch 56 tends to frictionally drive the metal plate 59 in a counterclockwise direction as shown by the arrow 69 during the closing direction of movement of the door 14.

A moving contact blade 71 is insulated from but moves with the metal plate 59. In the solid line position it is shown as interconnecting switch blades 72 and 73 and in the phantom line position shown it does not interconnect these two switch blades.

The control circuit 27 includes a relay 78 with a relay coil 79 acting through an armature 80, a stepping wheel 81, and a cam 82 to control actuation of contacts 83-86. These contacts are actuated closed in various sequence depending upon door opening, open, door closing, and door closed conditions. As explained below, the door control circuit 27 is illustrated in the door closing condition and as shown contacts 83, 85, and 86 are closed with contact 84 open. This provides direct energization to the motor winding 52 for a counterclockwise rotational direction of the torque switch 44 in FIG. 7. In the door open condition only contact 86 is closed to provide energization to a lamp 87 illuminating the inside of a garage. In the door opening condition, contacts 83,84, 86 are closed with contact open; and this provides direct energization of the motor winding 51 for a clockwise rotational direction of the motor rotor 54. For the door closed position, all contacts 83-86 are opened.

The upper end of the transformer secondary 47 connects to-a terminal 89 on a terminal strip 88 which strip tween terminals 90 and 91. The conductor 92 leads to the leaf spring contacts 65 and 72 of the torque switch 44 and also joins with a conductor 97 which connects through the relay contact 83 and the conductor 98 to i the leaf spring contact 66'. The leaf spring contact 66 is also connected through the up limit switch 22 'to Operation In the door closed condition all contacts 83-86 of the relay 78 are open. When the push button 95 is depressed, this energizes momentarily the relay 78 to cause the cam 82 to advance the contacts to the door opening condition. This closes contact 84 for direct energization of the motor winding 51. In the door opening condition, the one-way clutch 56 slips, and the torque switch 44 is not moved counterclockwise. Instead the weight 68 keeps the metal plate 59 in the phantom position. In this position the moving contact blade 71 does not close the switch blades 72 and 73 thus to disable the down limit switch 21. At the end of the up travel of the door the up limit switch 22 is actuated and this impulses the relay coil 79 to change to the door open condition whereat only contact 86 is closed.

If during the up travel of the door, the door meets an obstruction which slows the door travel, this can close the load switch 60, 61 which is centrifugally operated; and this will also impulse the relay to stop the door movement. When next the push button 95 or radio receiver contact 96 is actuated, this will again impulse the relay 78 to establish the door closing condition. In this condition the one-way clutch 56 frictionally drives the metal plate 59 counterclockwise in the direction of the arrow 69, despite the weight 68. If the door does not meet an obstruction during its door closing movement, then the door will continue until the down limit switch 21 is actuated. In the door closing direction shown in solid lines in FIG. 7, the moving contact blade 71 closes on the switch blade 72 and 73 to enable the down limit switch 21. Accordingly, when it is actuated this imdition where'at all contacts 83-86 are opened.

If duringthe door closing movement an obstruction is met which slows the door travel, such as 'would be caused by striking a child or a pet, then the torque switch 44 achieves the desirable result that the door not only stops but actually reverses and goes back to an open position. The clutch 55 may be adjusted to adjust the torque at which the clutch will slip and thus estab lish this safety reversing condition.

If an obstruction is met in the downward direction of the door, the load switch 60, 61 is closed and this gives a first impulse to the relay 78. This is causes by grounding of the hub 60 acting through contact 63, blade 66,

. and relay contact 83. This changes the relay condition to the door closed condition whereas contacts 84 and 85 are open. This is a cessation of torque from the deenergized motor 12 and accordingly the weight 68 swings the plate 59 clockwise to the phantom position. As it does so, there is a momentary engagement between the first contact 62 and the contactblade 65 which again impulses the relay 78 to the door opening condition. The aforementioned circuit gives the safety reverse condition in case an obstruction is met in the door closing movement. Such safety reverse is required to be operable when the door strikes an obstruction more than 1 9/16 inches away fromthe door sill 100,

see FIG. 4. As stated above, if the door is actually stopped by actuating the down limit switch 21, then it does not reverse. However, if the door is stopped by meeting an obstruction and slowing and first closing the load switch 60, 61, then the door does reverse to return pulses therelay 78 to changeit to the door closed conware 105. These illustrate alternative forms of doors which have different opening and closing characteris-' tics from the sectional door shown in FIG. 4. The present invention is made to be operable with all of these forms of doors and door hardware. It is also operable with a one-piece door the top of which moves horizontally along a straight track and a lower portion of the door which moves vertically along a vertical straight track.

To accomplish this desirable result of a travelling limit switch 21, the cycling means 29 is provided. This cycling means is responsive to a cycle of an opening and a closing movement of the motor output 13 and of the door carriage l6. Assume first that the door carriage is closing, that is, moving to the left in FIG. 1. As the carriage l6 completes its travel toward the travel limit, the actuator means 23 will actuate the switch 21. The actuator part 37 actually closes the limit switch 21 to de-energize the motor 12. However, practically all doors have some amount of coasting due to the inertia of the heavy'door. This coast may be only another l/8th of an inch for the'door 14 but may be, as'an example, 0.5 inches as anominal distance for coasting movement of the carriage 16 to the left. Actuator part 38 pushes against the switch frame 25 to move it a distance 0.5 inches to the left. In so doing, the actuator to the open position. It is noted in FIG. 4 there is a considerable toggle action in the final closing movement of the door 14. This is because the door carriage 16, acting through the arm 18 to the door 14, comes into a position generally vertically above the door 14. Accordingly, there is considerable movement of the carriage 16 for only a small amount of final closing movement of the door 14.

When the door sill 100 rises, e.g., 0.25 inches due to heaving by frost, then the door 14 will reach the end of its physical travel sooner than normal. Te carriage l6 accordingly might end its travel one inch to the right, see FIG. 1, of its normal position. In such case the down limit switch 21 might never be actuated and this means that the load switch 60, 61 would be actuated so that the door would go into its safety reverse and again open. This would prevent the owner of the garage from being able to close his garage door 14.

The present invention provides a travelling limit switch which automatically adjusts itself into proper position in accordance with the changing ambient con ditions. There are many different causes of the. door down limit change as follows:

1. Snow or ice may be packed on the door sill. 2. Snow or ice may be clinging to the bottom of the door. 3. Leaves or other debris may be packed under the door. 4. Frost may cause heaving of the sill 100. 5. High moisture content in a wooden door may increase the physical height of the door itself. 6. Moisture within a wooden door may increase the door thickness to wedge itself more quickly against the door frame 101 due to an inclined door track 102.

FIG. 5 shows a door 14A which is a one-piece door I pawl 39 slides past the ratchet wheel 34. The actuator means 39 will end in the phantom position 39A with the pawl tang 40 spaced from ratchet wheel 34 by a lost motion distance 107.

When a door opening condition is again initiated, the carriage 16 moves back to the right. This moves the actuator pawl 39 through this lost motion distance 107 and through a drive distance 108 during which the ratchet wheel 34 is rotated counterclockwise. During this distance the friction wheels 35 are turned and by frictionallyengaging the bottom of the guide rail 17 propel the switch frame 25 to the right by motion amplifying means a reference dimension 109. An example this might be 0.5 inches. Accordingly under normal conditions with the ambient conditions not changing, the switch frame 25 is cycled back and forth 0.5 inches, in the above example. The motion-amplifying means comes from the fact that the effective radius of the ratchet wheel 34 is less than the effective radius of the friction wheels 35. Accordingly the reference dimension 109 is larger than the drive distance 108 by the ratio of the radius of the friction wheels 35 to that of the ratchet wheel 34. Next suppose that the ambient includes freezing conditions outside and the ground under the sill heaves 0.1 inches overnight. This slightly raises the door 14 and jambs more tightly the door carriage 16 against the bottom of the guide rail 17. When the door is opened, the lost motion distance 107 will be taken up, the drive distance 108 will produce a motion amplified movement of the switch frame 25 so that it moves the reference dimension 109, namely 0.5 inches.

When next the garage door is closed, the door will not be able to close as far because it will strike the sill obstruction 0.1 inches sooner. For this sectional type door 14, the carriage 16 may have its limit 0.2 inches sooner. This means that the lost motion distance 107 will be lessened by 0.2 inches. It also means that the final closing movement of the door is such that the actuator part 38 moves the switch frame 25 to the left only 0.3 inches to compensate for the heaving of the door sill 100. When next the door 14 is opened, there will again be the reference dimension 109 of 0.5 inches because the same drive distance 108 is achieved and the same motion amplifying means; hence the refer ence dimension of 0.5 inches is achieved. The net result is that the switch frame 25 will gradually be moved along to the right the guide rail 17 as the door sill 100 heaves and the door is cycled. In the spring when the door sill settles back down, there will be a gradual cycling of the switch frame 25 so that it moves gradually back to the left. I 4

FIGS. 8, 9, and 10 show an alternative construction of a door operator control 1 11 which may use the same electrical control circuit 27 of FIG. 7. Like parts in the FIGS. 8, 9, and 10 to those in FIGS. 1, 2, and 3 have been given the same reference numerals. The switchframe 25A is slidable along the guide rail 17 and the axle 33 is carried therein in a vertical slot 112. The midportion of theaxle fixedly carries a worm wheel 113 capable of meshing with the worm 19 when lifted into engagement therewith as shown in FIG. 8. The actuator means 23A includes the actuator part 37 to close the down limit switch 21 and the actuator part 38 to physically move the switch frame 25A to the left. It also includes levers 114 pivoted at 1 on the door carriage 16 and urged upwardly by a spring 116.

, Operation I 8. This FIG. shows that the axle 33 has ridden up on the ramp 118 at the leading edge of the levers 114 to a position where the worm wheel 113 is just engaged with the worm 19. Since the .worm 19 is rotating in a direction to move the nut to the left, it will also move the top of the worm wheel 1 13 to the left for counterclockwise rotation. This rotation of the friction wheels 35 physically drives the switch frame A to the right relative to guide rail 17 a reference dimension 119. At the same time that this is happening, the levers 114 move to the left because they are attached to the door carriage 16, and this is an additional movement 120 so that the axle 33 drops into a notch 121 terminating the reference dimension movement. Shortly after the axle 33 drops into the notch 121, the actuator means closes the down limit switch 21 and the actuator part 38 pushes the switch frame 25A to the left during the distance that the door carriage 16 coasts. This is a coasting dis-' tance or may be considered a lost motion distance 1 17. Under normal conditions without any change of ambient condition, the reference dimension 119 equals the lost motion distance 117. The reference dimension 119 may be any suitable amount, for example 0.5 inches.

Assume that the door sill 100 has heaved slightly, then this would jamb the door carriage 16 more tightly against the guide rail 17. When next the door 14 is opened, the axle 33 rides underneath the overhanging flange of the ramp 118, thus lifting the levers 114 to permit the axle 33 to pass under this flange of the ramp 118. When next the door 14 is closed, the carriage 16 will not be able to go as far to the left as before, because of the raised door sill 100. As the door carriage l6 approaches its closed limit position, the axle 33will again ride up on the ramp 118 to engage the worm wheel 113 with the worm 19. This moves the switch frame 25A to the right of the reference dimension 119. When the axle 33 drops into the notch 121, this reference dimension movement is terminated'and shortly thereafter the limit switch 21 is actuated. Because of the raised door sill, the coasting distance or lost-motion distance 117 will be less and hence the movement to the left of the switch frame 25A will be less, e.g., 0.4 inches. Accordingly it will be seen that the switch frame 25A has moved .to the right 0.1 inches during that cycle of door opening and closing movement. Should the ambient conditions change and the door sill go back down, then the coasting distance will be greater, e.g., 0.6 inches, and the total effect will be that the limit switch frame 25A will move back to the left.

Accordingly, it will be seen that the cycling means 29 has means to establish a reference dimension 109 or 119. The cycling means 29 may also be considered as including differential measuring means which measure the difference between the reference dimension and a part of one of said opening and closing movements of the motor output 13, 16. The cycling means includes comparison means because the reference dimension is being compared with a portion of the opening and closing movement. In FIGS. 1-3 and 8l0 the reference dimension is compared with the last portion of the closing movement of the door. In FIGS. 1-3 the reference dimension is obtained at the beginning of the door opening movement. In FIGS. 8-10 the reference dimension is obtained at the last portion of the closing movement of the door. There is a frame 25 for the switch and a frame 26 for the actuator 23. Te cycling means moves one of these frames and in the preferred embodiments this is a movement of the switch frame. The switch includes first and second contacts 31 and 32 and this movement is of at least one of these two contacts. One frame is on the guide rail, and one frame is on the carriage; and this movement of one frame is relative to either the carriage or the guide rail and in this preferred embodiment is relative to the guide rail 17. The power for movement of the switch frame 25 or 25A comes from the power to move the door itself. In both embodiments shown the means to establish the reference dimension derives power from the motor 12 via the agency of the ratchet wheel 34 and pawl 39 or the worm wheel 113 and worm 19. Also the return movement of the switch frame 25 or 25A comes from being pushed by the door carriage 16 during the coasting movement. The present disclosure includes that contained in th appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

WHAT IS CLAIMED IS:

1. A door operator control including a motor having an output connected to move the door between open and closed limit positions, said door being adapted to have a changing limit position due to changing ambient conditions,

said control including limit switch means,

actuator means for said limit switch means,

means connecting said switch means to control said motor output in at least one of opening and closing movements, and cycling means connected to relatively move the point of switch actuation by said actuator means in accordance with changes in a limit position of the door.

2. A door operator control as claimed in claim 1, wherein said cycling means includes means responsive to a cycle of an opening and a closing movement of said motor output.

3. A door operator control as claimed in claim 1, wherein said cycling means includes means establishing a reference, and comparison means connected to compare the difference between said reference and at least a part of one of said opening and closing movements.

4. A door operator control as claimed in claim 1, wherein said cycling means includes means establishing a reference dimension,

and differential measuring means connected to measure the difference between said reference dimension and one of said opening and closing movements of said motor output.

5. A door operator control as claimed in claim 4, wherein said means establishing a reference dimension includes means to obtain a movement from a portion of one of said opening and closing movements of said motor output.

6. A door operator control as claimed in claim 5, wherein said differential measuring means includes means to measure a portion of one of said opening and closing movements.

7. A door operator control as claimed in claim 1, wherein said cycling means moves one of said actuator means and switch means.

8. A door operator control as claimed in claim 1, wherein said switch means has first and second contacts, and said cycling means moves at least one contact of said switch means.

9. A door operator control as claimed in claim 1, wherein said cycling means moves said switch means to a different position for actuation of said switch means by said actuator means and consequent change of condition of said motor output at a different position in accordance with changes in a limit position of the door.

10. A door operator control as claimed in claim 1, wherein said cycling means includes means deriving power from one of said opening and closing movements of said motor output to physically move one of said switch and actuator means along a mounting therefor.

wherein said power deriving means establishes said first and second opposing directions of movement of said switch means as being of different amounts upon'a change in a limit position of the door.

13. A door operator control as claimed in claim 4, wherein said means establishing a reference dimension includes a motion amplifying means.

14. A door operator control as claimed in claim 4, wherein said means establishing a reference dimension includes lost motion means.

15. A door operator control as claimed in claim 14, including a frame for said switch means,

A frame for said actuator means,

a carriage movable on a guide rail and connected to said motor output and to a door to move same between open and closed positions,

and means mounting one frame on said carriage and the other frame on the guide rail.

16. A door operator control as claimed in claim 15, wherein said reference dimension establishing means includes an axle journalled on one frame,

a one-way ratchet'wheel fixed on said axle,

and a wheel fixed on said axle to frictionally roll on and a wheel fixed on said axle to frictionally roll on and propel said one frame on one of said rail and carriage.

17. A door operator control as claimed in claim 16, wherein said reference dimension establishing means includes a pawl mounted on the other of said frames and cooperable with said ratchet wheel.

18. A door operator control as claimed in claim 16, including motion amplifying means established by said ratchet wheel having an effective radius less than that of said wheel.

19..A door operator control as claimed in claim 1, wherein said cycling means includes means responsive to only one of said opening and closing movements.

20. A door operator control as claimed in claim 4, including said reference dimension establishing means being responsive to only one of said opening and closing movements, and said differential measuring means being responsive to only said one of said opening and closing movements.

21. A door operator control as claimed in claim 4, including said reference dimension establishing means being responsive to only one of said opening and closing movements, v

and said differential measuring means being responsive to only said other of said opening and closing movements.

22. A door operator control as claimed in claim 4, wherein said differential measuring means includes means to relatively move said switch and actuator means in a direction opposite to the relative movement between said switch and actuator means established by said reference dimension establishing means.

23. A door operator control as claimed in claim 1, wherein said cycling means includes lost motion means.

24. A door operator control as claimed in claim 1, wherein said cycling means includes motion amplifying means. 

1. A door operator control including a motor having an output connected to move the door between open and closed limit positions, said door being adapted to have a changing limit position due to changing ambient conditions, said control including limit switch means, actuator means for said limit switch means, means connecting said switch means to control said motor output in at least one of opening and closing movements, and cycling means connected to relatively move the point of switch actuation by said actuator means in accordance with changes in a limit position of the door.
 2. A door operator control as claimed in claim 1, wherein said cycling means includes means responsive to a cycle of an opening and a closing movement of said motor output.
 3. A door operator control as claimed in claim 1, wherein said cycling means includes means establishing a reference, and comparison means connected to compare the difference between said reference and at least a part of one of said opening and closing movements.
 4. A door operator control as claimed in claim 1, wherein said cycling means includes means establishing a reference dimension, and differential measuring means connected to measure the difference between said reference dimension and one of said opening and closing movements of said motor output.
 5. A door operator control as claimed in claim 4, wherein said means establishing a reference dimension includes means to obtain a movement from a portion of one of said opening and closing movements of said motor output.
 6. A door operator control as claimed in claim 5, wherein said differential measuring means includes means to measure a portion of one of said opening and closing movements.
 7. A door operator control as claimed in claim 1, wherein said cycling means moves one of said actuator means and switch means.
 8. A door operator control as claimed in claim 1, wherein said switch means has first and second contacts, and said cycling means moves at least one contact of said switch means.
 9. A door operator control as claimed in claim 1, wherein said cycling means moves said switch means to a different position for actuation of said switch means by said actuator means and consequent change of condition of said motor output at a different position in accordance with changes in a limit position of the door.
 10. A door operator control as claimed in claim 1, wherein said cycling means includes means deriving power from one of said opening and closing movements of said motor output to physically move one of said switch and actuator means along a mounting therefor.
 11. A door operator control as claimed in claim 10, wherein said power deriving means moves said switch means in first and second opposing directions in a complete cycle of opening and closing movements of said motor output.
 12. A door operator control as claimed in claim 11, wherein said power deriving means establishes said first and second opposing directions of movement of said switch means as being of different amounts upon a change in a limit position of the door.
 13. A door operator control as claimed in claim 4, wherein said means establishing a reference dimension Includes a motion amplifying means.
 14. A door operator control as claimed in claim 4, wherein said means establishing a reference dimension includes lost motion means.
 15. A door operator control as claimed in claim 14, including a frame for said switch means, A frame for said actuator means, a carriage movable on a guide rail and connected to said motor output and to a door to move same between open and closed positions, and means mounting one frame on said carriage and the other frame on the guide rail.
 16. A door operator control as claimed in claim 15, wherein said reference dimension establishing means includes an axle journalled on one frame, a one-way ratchet wheel fixed on said axle, and a wheel fixed on said axle to frictionally roll on and a wheel fixed on said axle to frictionally roll on and propel said one frame on one of said rail and carriage.
 17. A door operator control as claimed in claim 16, wherein said reference dimension establishing means includes a pawl mounted on the other of said frames and cooperable with said ratchet wheel.
 18. A door operator control as claimed in claim 16, including motion amplifying means established by said ratchet wheel having an effective radius less than that of said wheel.
 19. A door operator control as claimed in claim 1, wherein said cycling means includes means responsive to only one of said opening and closing movements.
 20. A door operator control as claimed in claim 4, including said reference dimension establishing means being responsive to only one of said opening and closing movements, and said differential measuring means being responsive to only said one of said opening and closing movements.
 21. A door operator control as claimed in claim 4, including said reference dimension establishing means being responsive to only one of said opening and closing movements, and said differential measuring means being responsive to only said other of said opening and closing movements.
 22. A door operator control as claimed in claim 4, wherein said differential measuring means includes means to relatively move said switch and actuator means in a direction opposite to the relative movement between said switch and actuator means established by said reference dimension establishing means.
 23. A door operator control as claimed in claim 1, wherein said cycling means includes lost motion means.
 24. A door operator control as claimed in claim 1, wherein said cycling means includes motion amplifying means. 